Array substrate and method for manufacturing the same, method and assembly for detecting light, and display device

ABSTRACT

An array substrate and a method for manufacturing the same, a method and assembly for detecting light, and a display device are provided. The array substrate includes: a base substrate having a pixel region; a light detecting unit, a switch unit, and a light emitting unit that are located in the pixel region, where the light emitting unit and the light detecting unit share the switch unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure is a 371 of PCT Application PCT/CN2020/092374filed on May 26, 2020, which claims priority to Chinese PatentApplication No. 201910452554.8, filed on May 28, 2019 and titled “ARRAYSUBSTRATE, METHOD AND ASSEMBLY FOR DETECTING LIGHT, AND DISPLAY DEVICE”,which are incorporated herein by reference in their entireties.

TECHNICAL FIELD

The present disclosure relates to an array substrate and a method formanufacturing the same, a method and assembly for detecting light, and adisplay device.

BACKGROUND

With the development of display technology, more and more displayproducts are integrated with a light detecting unit to achieve lightdetection functions. For example, a display product integrated with alight detecting unit can detect the ambient light in the environmentwhere the display product is located. Generally, the light detectingunit may be integrated on the array substrate of the display product.

SUMMARY

The present disclosure provides an array substrate and a method formanufacturing the same, a method and assembly for detecting light, and adisplay device. The technical solution of the present disclosure is asfollows.

In a first aspect, an array substrate is provided. The array substrateincludes:

a base substrate having a pixel region; and

a light detecting unit, a switch unit, and a light emitting unit thatare located in the pixel region, where the light detecting unit and thelight emitting unit share the switch unit.

In some embodiments, the switch unit is located on the side away from aphotosensitive layer of the light detecting unit, the switch unit isinsulated from the light detecting unit, and the orthographic projectionof the light detecting unit on the base substrate is at least partiallyoverlapped with the orthographic projection of the switch unit on thebase substrate.

The switch unit is electrically connected to the light emitting unit.

In some embodiments, the orthographic projection of the switch unit onthe base substrate covers the orthographic projection of the lightdetecting unit on the base substrate.

In some embodiments, the light detecting unit includes a firstelectrode, a photosensitive layer, and a second electrode that aresequentially stacked in a direction close to the switch unit.

The switch unit includes an active layer, a control terminal, a firstterminal, and a second terminal, where the control terminal, the firstterminal, and the second terminal are located on the side of the activelayer away from the light detecting unit, and one of the first terminaland the second terminal is the source, and the other thereof is thedrain.

In some embodiments, the second electrode is made of a light-shieldingmaterial, and the orthographic projection of the second electrode on thebase substrate is at least partially overlapped with the orthographicprojection of the active layer on the base substrate.

In some embodiments, the orthographic projection of the second electrodeon the base substrate covers the orthographic projection of the activelayer on the base substrate.

In some embodiments, the light emitting unit is an electroluminescentunit, and the first terminal of the switch unit is electricallyconnected to an anode of the light emitting unit.

In some embodiments, the array substrate further includes:

an insulating layer located between the light detecting unit and theswitch unit;

a planarization layer located between the switch unit and the lightemitting unit; and,

a pixel defining layer located on the side of the planarization layeraway from the switch unit, where the light emitting unit is located in apixel opening defined by the pixel defining layer.

In some embodiments, the light detecting unit, the switch unit, and thelight emitting unit are sequentially distributed in a direction awayfrom the base substrate, and the array substrate further includes:

an encapsulation layer located on the side of the light emitting unitaway from the base substrate.

In a second aspect, a method for detecting light is provided for use inthe array substrate according to the first aspect or any optional mannerof the first aspect, and the light detecting unit of the array substrateincludes a first electrode, a photosensitive layer, and a secondelectrode. The method for detecting light includes:

controlling the switch unit to operate in an ON transition region, wherethe ON transition region is the region between an ON region and an OFFregion of the switch unit;

applying a voltage to the first electrode of the light detecting unit,so that the second electrode of the light detecting unit has apotential, where the potential of the second electrode changes under theaction of the light irradiated to the first electrode, causing an outputcurrent of the switch unit to change;

determining an amount of change of the output current of the switchunit; and

determining an intensity of illumination irradiated to the firstelectrode based on the amount of change of the output current of theswitch unit.

In some embodiments, the light irradiated to the first electrode is thelight reflected by a fingerprint, and after determining the amount ofchange of the output current of the switch unit, the method fordetecting light further includes:

performing fingerprint detection based on the amount of change of theoutput current of a plurality of the switch units.

In a third aspect, an assembly for detecting light is provided for usein the array substrate according to the first aspect or any optionalmanner of the first aspect, and the light detecting unit of the arraysubstrate includes a first electrode, a photosensitive layer, and asecond electrode. The assembly for detecting light includes:

a controlling module, configured to control the switch unit to operatein an ON transition region, where the ON transition region is the regionbetween an ON region and an OFF region of the switch unit;

a voltage applying module, configured to apply a voltage to the firstelectrode of the light detecting unit, so that the second electrode ofthe light detecting unit has a potential, where the potential of thesecond electrode changes under the action of the light irradiated to thefirst electrode, causing an output current of the switch unit to change;

a first determining module, configured to determine an amount of changeof the output current of the switch unit; and

a second determining module, configured to determine an intensity ofillumination irradiated to the first electrode based on the amount ofchange of the output current of the switch unit.

In some embodiments, the light irradiated to the first electrode is thelight reflected by a fingerprint, and the assembly for detecting lightfurther includes:

a detecting module, configured to perform fingerprint detection based onthe amount of change of the output current of a plurality of the switchunits.

In a fourth aspect, a method for manufacturing an array substrate isprovided.

The method for manufacturing an array substrate includes:

providing a base substrate having a pixel region;

forming a light detecting unit, a switch unit, and a light emitting unitin the pixel region so that the light detecting unit and the lightemitting unit share the switch unit.

In some embodiments, forming the light detecting unit, the switch unit,and the light emitting unit in the pixel region so that the lightdetecting unit and the light emitting unit share the switch unitincludes:

forming the light detecting unit in the pixel region;

forming the switch unit on the side of the light detecting unit awayfrom the photosensitive side of the light detecting unit, where theswitch unit is insulated from the light detecting unit, and theorthographic projection of the light detecting unit on the basesubstrate is at least partially overlapped with the orthographicprojection of the switch unit on the base substrate; and

forming the light emitting unit on the side of the switch unit away fromthe light detecting unit, where the light emitting unit is electricallyconnected to the switch unit.

In some embodiments, forming the light detecting unit in the pixelregion includes:

forming a first electrode, a photosensitive layer, and a secondelectrode in the pixel region, where the first electrode, thephotosensitive layer, and the second electrode are sequentially stackedin a direction away from the base substrate.

Forming the switch unit on the side of the light detecting unit awayfrom the photosensitive side of the light detecting unit includes:

forming an active layer on the side of the light detecting unit awayfrom the photosensitive side of the light detecting unit; and

forming a control terminal, a first terminal, and a second terminal onthe side of the active layer away from the light detecting unit, whereone of the first terminal and the second terminal is a source, and theother thereof is a drain.

In some embodiments, before forming the switch unit on the side of thelight detecting unit away from the photosensitive side of the lightdetecting unit, the method for manufacturing an array substrate furtherincludes:

forming an insulating layer on the side of the light detecting unit awayfrom the photosensitive side of the light detecting unit;

forming the switch unit on the side of the light detecting unit awayfrom the photosensitive side of the light detecting unit includes:

forming the switch unit on the side of the insulating layer away fromthe light detecting unit.

In some embodiments, before forming the light emitting unit on the sideof the switch unit away from the light detecting unit, the method formanufacturing an array substrate further includes:

forming a planarization layer on the side of the switch unit away fromthe light detecting unit;

forming the light emitting unit on the side of the switch unit away fromthe light detecting unit includes:

forming the light emitting unit on the side of the planarization layeraway from the light detecting unit;

the method for manufacturing an array substrate further includes:forming a pixel defining layer on the side of the planarization layeraway from the switch unit, where the light emitting unit is located in apixel opening defined by the pixel defining layer.

In some embodiments, the method for manufacturing an array substratefurther includes:

forming an encapsulation layer on the side of the light emitting unitaway from the base substrate.

In a fourth aspect, a display device is provided, including the arraysubstrate according to the first aspect or any optional manner of thefirst aspect.

In some embodiments, the display device further includes the assemblyfor detecting light according to the third aspect or any optional mannerof the third aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

To describe the technical solutions in the embodiments of the presentdisclosure more clearly, the following briefly introduces theaccompanying drawings required for describing the embodiments.Apparently, the accompanying drawings in the following description showmerely some embodiments of the present disclosure, and a person ofordinary skill in the art may still derive other drawings from theseaccompanying drawings without creative efforts.

FIG. 1 is a front view of an array substrate according to an embodimentof the present disclosure;

FIG. 2 is a cross-sectional view of the portion a-a of the arraysubstrate shown in FIG. 1 ;

FIG. 3 is a front view of another array substrate according to anembodiment of the present disclosure;

FIG. 4 is a cross-sectional view of the portion a-a of the arraysubstrate shown in FIG. 3 ;

FIG. 5 is a principle diagram of light detection performed by a lightdetecting unit according to an embodiment of the present disclosure;

FIG. 6 is a graph showing the illumination time versus the potential ofthe first electrode according to an embodiment of the presentdisclosure;

FIG. 7 is a graph showing the control voltage of the switch unit versusthe output current of the switch unit according to an embodiment of thepresent disclosure;

FIG. 8 is an equivalent circuit diagram of an array substrate accordingto an embodiment of the present disclosure;

FIG. 9 is a graph of the transfer characteristics of the switch unitaccording to an embodiment of the present disclosure;

FIG. 10 is a flow chart of a method for manufacturing an array substrateaccording to an embodiment of the present disclosure;

FIG. 11 is a flow chart of another method for manufacturing an arraysubstrate according to an embodiment of the present disclosure;

FIG. 12 to FIG. 16 are schematic diagrams of a process for manufacturingan array substrate according to an embodiment of the present disclosure;

FIG. 17 is a flow chart of a method for detecting light according to anembodiment of the present disclosure;

FIG. 18 is a flow chart of another method for detecting light accordingto an embodiment of the present disclosure;

FIG. 19 is a block diagram of an assembly for detecting light accordingto an embodiment of the present disclosure; and

FIG. 20 is a block diagram of another assembly for detecting lightaccording to an embodiment of the present disclosure.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments consistent with thepresent disclosure, and together with the description, serve to explainthe principles of the present disclosure.

DETAILED DESCRIPTION

For clearer descriptions of the principles, technical solutions andadvantages of the present disclosure, the present disclosure isdescribed in detail below in combination with the accompanying drawings.Apparently, the described embodiments are merely some embodiments,rather than all embodiments, of the present disclosure. Based on theembodiments of the present disclosure, all other embodiments derived bya person of ordinary skill in the art without creative efforts shallfall within the protection scope of the present disclosure.

With the development of display technology, the light detecting unit maybe integrated on the array substrate, so that the array substrate canrealize the light detection function. For example, the array substrateintegrated with the light detecting unit can detect the ambient light inthe environment where the array substrate is located, and again forexample, the array substrate integrated with the light detecting unitcan detect the light emitted from the light emitting unit of the arraysubstrate. At present, the array substrate integrated with the lightdetecting unit includes: a base substrate, a light emitting unit, alight detecting unit, and a thin film transistor (TFT), where the lightemitting unit, the light detecting unit and the thin film transistor arelocated on the base substrate, and the base substrate has a plurality ofpixel regions arranged in an array. Currently, each of the pixel regionsis provided with a light emitting unit, a light detecting unit and twoTFTs. The two TFTs are distributed in the same layer, and the lightemitting unit and the light detecting unit are independently controlledby the two TFTs respectively.

However, such an array substrate has a large number of TFTs, whichresults in a complex structure of the array substrate. In addition,since the two TFTs are distributed in the same layer, the light emittingunit and the light detecting unit occupy a relatively low area of thepixel region, which results in low pixel filling rates and low detectionresolutions of the array substrate.

Reference is made to FIG. 1 and FIG. 2 , FIG. 1 is a front view of anarray substrate according to an embodiment of the present disclosure,and FIG. 2 is a cross-sectional view of the portion a-a of the arraysubstrate shown in FIG. 1 . Referring to FIG. 1 and FIG. 2 , the arraysubstrate includes: a base substrate 11 having a pixel region P; a lightdetecting unit 12, a switch unit 13 and a light emitting unit 14 thatare located in the pixel region P. The light detecting unit 12 and thelight emitting unit 14 share the switch unit 13.

Those skilled in the art can easily understand that the base substrate11 has a plurality of pixel regions P arranged in an array. In theembodiment of the present disclosure, each of the pixel regions P isprovided with a light detecting unit 12, a switch unit 13 and a lightemitting unit 14, the light detecting unit 12 and the light emittingunit 14 in each of the pixel regions P share the switch unit 13 in thepixel region P.

In summary, with respect to the array substrate according to theembodiment of the present disclosure, the light emitting unit and thelight detecting unit share the switch unit in the pixel region, whichhelps to reduce the number of the switch units on the array substrate,thereby simplifying the structure of the array substrate.

In some embodiments, the light detecting unit 12 has a photosensitiveside, the switch unit 13 is located on a side away from thephotosensitive side of the light detecting unit 12, the switch unit 13is insulated from the light detecting unit 12, an orthographicprojection of the light detecting unit 12 onto the base substrate 11 isat least partially overlapped with an orthographic projection of theswitch unit 13 onto the base substrate 11, and the switch unit 13 iselectrically connected to the light emitting unit 14. In someembodiments, the photosensitive side of the light detecting unit 12 isthe side of the light detecting unit 12 close to the base substrate 11,as shown in FIG. 2 , the switch unit 13 is located on the side facingaway from the photosensitive side of the light detecting unit 12, thatis, the switch unit 13 is located on the side of the light detectingunit 12 away from the base substrate 11. Under the irradiation of light,the light detecting unit 12 can generate current, and the currentgenerated by the light detecting unit 12 can affect the output currentof the switch unit 13. When the switch unit 13 operates in the ONtransition region, the current generated by the light detecting unit 12has significant influence on the output current of the switch unit 13.Therefore, the intensity of illumination irradiated to the lightdetecting unit 12 (that is, the intensity of the light irradiated to thelight detecting unit 12) may be determined based on the amount of changeof the output current of the switch unit 13 when the switch unit 13operates in the ON transition region. In the embodiment of the presentdisclosure, the switch unit 13 may be controlled to operate in the ONtransition region, so that the switch unit 13 controls the lightdetecting unit 12 to perform light detection; and since the switch unit13 is electrically connected to the light emitting unit 14, the switchunit 13 can control the light emitting unit 14 to emit light, and thusthe switch unit 13 can control the light detecting unit 12 and the lightemitting unit 14 to realize that the light detecting unit 12 and thelight emitting unit 14 share the switch unit 13. The ON transitionregion is the region between an ON region and an OFF region of theswitch unit. For example, the region between an ON region and an OFFregion of a TFT is the subthreshold swing (SS) region. When the switchunit is a TFT, the ON transition region may be the SS region.

In some embodiments, the orthographic projection of the light detectingunit 12 onto the base substrate 11 is at least partially overlapped withthe orthographic projection of the switch unit 13 onto the basesubstrate 11. For example, the orthographic projection of the switchunit 13 onto the base substrate 11 covers the orthographic projection ofthe light detecting unit 12 onto the base substrate 11. Since the switchunit 13 is located on the side of the light detecting unit 12 away fromthe base substrate 11, and the orthographic projection of the lightdetecting unit 12 onto the base substrate 11 is at least partiallyoverlapped with the orthographic projection of the switch unit 13 ontothe base substrate 11, the vertical distribution of the switch unit 13and the light detecting unit 12 helps to reduce the occupied area of theswitch unit 13 in the pixel region P, and to improve the pixel fillingrate and detection resolution of the array substrate. The verticaldistribution refers to distribution along a direction perpendicular tothe surface of the base substrate 11. It is easy to understand that, thefact that the orthographic projection of the switch unit 13 onto thebase substrate 11 covers the orthographic projection of the lightdetecting unit 12 onto the base substrate 11, helps to reduce theoccupied area of the switch unit 13 in the pixel region P to thegreatest extent, and to improve the pixel filling rate and detectionresolution of the array substrate.

In some embodiments, as shown in FIG. 2 , the light detecting unit 12includes a first electrode 121, a photosensitive layer 122, and a secondelectrode 123 that are sequentially stacked in a direction close to theswitch unit 13. The switch unit 13 includes: an active layer 131, acontrol terminal 132, a first terminal 133, and a second terminal 134,where the control terminal 132, the first terminal 133, and the secondterminal 134 are located on the side of the active layer 131 away fromthe light detecting unit 12; one of the first terminal 133 and thesecond terminal 134 is the source, and the other thereof is the drain,and the first terminal 133 and the second terminal 134 are electricallyconnected to the active layer 131 respectively. Since the arraysubstrate determines the intensity of illumination irradiated to thelight detecting unit 12 based on the influence of the current generatedby the light detecting unit 12 on the output current of the switch unit13 under the irradiation of light, and thus the light detection isperformed, and the output current of the switch unit 13 is related tothe active layer 131, if the control terminal 132 is located on the sideof the active layer 131 close to the light detecting unit 12, thecontrol terminal 132 will shield the active layer 131, which causes theinfluence of the current generated by the light detecting unit 12 on theoutput current of the switch unit 13 to be reduced or even disappeared,and thus it is difficult to realize light detection. In the embodimentof the present disclosure, the control terminal 132 is located on theside of the active layer 131 away from the light detecting unit 12,which helps to prevent the control terminal 132 from shielding theactive layer 131, thereby avoiding the influence of the currentgenerated by the light detecting unit 12 on the output current of theswitch unit 13 to be reduced or even disappeared, and thus it is easy torealize light detection. In the embodiment of the present disclosure,the light irradiated to the light detecting unit 12 may be the lightemitted from the light emitting unit 14 or the light in the environmentwhere the array substrate is located, which is not limited in theembodiment of the present disclosure.

In some embodiments, the light detecting unit 12 may be a photodiode,the photosensitive layer 122 may be a PIN layer, and the switch unit 13may be a TFT. The control terminal 132 may be the gate, the firstterminal 133 may be the drain, and the second terminal 134 may be thesource. The first terminal 133 and the second terminal 134 may bedistributed in the same layer, and the first terminal 133 and the secondterminal 134 may be prepared through the same one patterning process. Asshown in FIG. 2 , the switch unit 13 further includes a gate insulatinglayer 135 located between the active layer 131 and the control terminal132, and an interlayer dielectric layer 136 located between the controlterminal 132 and the first terminal 133 and the second terminal 134.Each of the gate insulating layer 135 and the interlayer dielectriclayer 136 has a communicable first connection hole (for example, a drainvia) and a communicable second connection hole (for example, a sourcevia). The first terminal 133 is electrically connected to the activelayer 131 sequentially through the first connection hole in theinterlayer dielectric layer and the first connection hole in the gateinsulating layer 135, and the second terminal 134 is electricallyconnected to the active layer 131 sequentially through the secondconnection hole in the interlayer dielectric layer and the secondconnection hole in the gate insulating layer 135.

In some embodiments, the second electrode 123 may be made of alight-shielding material, and the orthographic projection of the secondelectrode 123 onto the base substrate 11 is at least partiallyoverlapped with the orthographic projection of the active layer 131 ontothe base substrate 11. In some embodiments, the orthographic projectionof the second electrode 123 onto the base substrate 11 covers theorthographic projection of the active layer 131 onto the base substrate11. In this way, the second electrode 123 may be used as a light shield(LS) layer to shield the active layer 131, which prevents light fromirradiating from the side where the base substrate 11 is located to theactive layer 131 to affect the characteristics of the active layer 131,thereby avoiding the influence of illumination on the switchingcharacteristics of the switch unit 13.

In some embodiments, the first electrode 121 may be made of transparentconductive materials such as indium tin oxide (ITO), indium zinc oxide(IZO) or aluminum-doped zinc oxide (ZnO:Al). The thickness of the firstelectrode 121 may range from 50 nm to 130 nm (nanometer); thephotosensitive layer 122 (for example, the PIN layer) may include aP-type semiconductor layer, an intrinsic semiconductor layer, and anN-type semiconductor layer that are sequentially stacked. The P-typesemiconductor layer may be close to the first electrode 121 or far awayfrom the first electrode 121 relative to the N-type semiconductor layer.The P-type semiconductor layer may be a P-type doped amorphous-silicon(a-Si) film layer, and the thickness of the P-type semiconductor layermay range from 10 nm to 20 nm. The intrinsic semiconductor layer may bean a-Si film layer, and the thickness of the intrinsic semiconductorlayer may range from 500 nm to 1000 nm. The N-type semiconductor layermay be an N-type doped a-Si film layer, and the thickness of the N-typesemiconductor layer may range from 10 nm to 20 nm. For example, theP-type semiconductor layer is doped with boron ions, and the N-typesemiconductor layer is doped with phosphorus ions. The second electrode123 may be made of magnesium (Mg), silver (Ag), molybdenum (Mo), copper(Cu), aluminum (Al), gold (Au) and alloy materials thereof, and thethickness of the second electrode 123 may range from 200 nm to 400 nm.

In some embodiments, the active layer 131 may be an oxide active layer,an a-Si active layer, or a p-Si active layer. The oxide active layer isfor example an indium gallium zinc oxide (IGZO) active layer or anindium tin zinc oxide (ITZO) active layer. The portion of the activelayer 131 connected to the first terminal 133 or the second terminal 134is metallized, so as to increase the carrier concentration of theportion and to ensure an ohmic contact between the portion and thecorresponding electrode (for example, the first terminal or the secondterminal). The gate insulating layer 135 may be made of transparentinsulating materials such as silicon dioxide (SiO₂), silicon oxide(SiO_(x)), silicon nitride (SiN_(x)), aluminium oxide (Al₂O₃) or siliconoxynitride (SiO_(x)N_(x)); the gate insulating layer 135 may be asingle-layered or multi-layered structure, for example, the gateinsulating layer 135 may be a SiO₂ single-layered structure or aSiN/SiO₂ multi-layered structure (that is, a multi-layered structureformed by alternately stacking SiN film layers and SiO₂ film layers);and the thickness of the gate insulating layer 135 may range from 80 nmto 150 nm. The control terminal 132 may be made of Mo, Cu, Al, Au andalloy materials thereof; and the thickness of the control terminal 132may range from 200 nm to 400 nm. The interlayer dielectric layer 136 maybe made of transparent insulating materials such as SiO₂, SiO_(x),SiN_(x), Al₂O₃ or SiO_(x)N_(x); the interlayer dielectric layer 136 maybe a single-layered or multi-layered structure, for example, theinterlayer dielectric layer 136 may be a SiO₂ single-layered structureor a SiN/SiO₂ multi-layered structure; and the thickness of theinterlayer dielectric layer 136 may range from 80 nm to 150 nm. Thefirst terminal 133 and the second terminal 134 may both be made of Mg,Ag, Mo, Cu, Al, Au and alloy materials thereof; and the thickness of thefirst terminal 133 and the thickness of the second terminal 134 mayrange from 200 nm to 400 nm.

In some embodiments, the light emitting unit 14 may be anelectroluminescent unit, as shown in FIG. 1 , the light emitting unit 14includes an anode 141, an electroluminescent layer 142, and a cathode143 that are sequentially stacked in a direction away from the basesubstrate 11, and the anode 141 is electrically connected to the firstterminal 133. The electroluminescent unit may be an organic lightemitting diode (OLED) unit or a quantum dot light emitting diode (QLED)unit. The anode 141 may be made of Mg, Ag, Mo, Cu, Al, Au and alloymaterials thereof. The cathode 143 may be made of conductive materialssuch as ITO, IZO or metal Ag; and for example, the cathode 143 is anITO/Ag/ITO multi-layered structure, where the thickness of the ITO filmlayer is 8 nm, and the thickness of the Ag film layer is 100 nm. Thoseskilled in the art can easily understand that, the electroluminescentunit includes two electrodes and an electroluminescent layer sandwichedbetween the two electrodes. The embodiment of the present disclosure isdescribed by taking an example in which the two electrodes includes ananode 141 and a cathode 143, and the anode is electrically connected tothe first terminal 133 of the switch unit 13, and the cathode is notelectrically connected to the switch unit 13. In actual applications,the cathode may be electrically connected to the first terminal 133 ofthe switch unit 13, and the anode may be not electrically connected tothe switch unit 13, and in different scenarios, the names of the abovetwo electrodes may also be other names. Furthermore, the light emittingunit 14 shown in FIG. 1 and FIG. 2 is only exemplary. In actualapplications, the light emitting unit 14 may also include a holeinjection layer, a hole transport layer, an electron transport layer,and an electron injection layer, which will not be repeated in theembodiment of the present disclosure.

In some embodiments, as shown in FIG. 1 , the array substrate furtherincludes a plurality of gate lines 19 and a plurality of data lines 20,and the plurality of gate lines 19 and the plurality of data lines 20are insulated and crossed to define a plurality of pixel regions P, Thecontrol terminal 132 (for example, the gate) of the switch unit 13 maybe electrically connected to the gate line 19, the second terminal 134(for example, the source) of the switch unit 13 may be electricallyconnected to the data line 20, The gate line 19 is used to apply acontrol voltage to the control terminal 132, and the data line 20 isused to apply a data voltage to the second terminal 134. In someembodiments, the gate line 19 and the control terminal 132 may bedistributed in the same layer, and the gate line 19 and the controlterminal 132 may be prepared through the same one patterning process.The data line 20 and the second terminal 134 are distributed in the samelayer, and the data line 20 and the second terminal 134 may be preparedthrough the same one patterning process.

In some embodiments, as shown in FIG. 2 , the array substrate furtherincludes an insulating layer 15 located between the light detecting unit12 and the switch unit 13; a planarization layer 16 located between theswitch unit 13 and the light emitting unit 14; and a pixel defininglayer 17 located on the side of the planarization layer 16 away from theswitch unit 13. The pixel defining layer 17 defines a pixel opening K,the orthographic projection of the pixel opening K onto the basesubstrate 11 is located within the pixel region P, and the lightemitting unit 14 is located within the pixel opening K defined by thepixel defining layer 17. The insulating layer 15 may include an organicinsulating layer and an inorganic insulating layer that are stacked. Theorganic insulating layer may be made of resin, and the differencebetween the thickness of the organic insulating layer and the thicknessof the light detecting unit 12 may range from 1.2 μm to 3 μm(micrometers). The inorganic insulating layer may be a single-layered ormulti-layered structure, for example, the inorganic insulating layer maybe an SiO₂ single-layered structure or a SiN/SiO₂ multi-layeredstructure. The planarization layer 16 may be made of resin, and thethickness of the planarization layer 16 may range from 2 μm to 3 μm. Thepixel defining layer 17 may be made of resin with strong liquidrepellency (for example, hydrophobicity). The electroluminescent layer142 is usually formed by an inkjet printing process or a solution-basedprocess. The pixel defining layer 17 being made of resin with strongliquid repellency can facilitate printing of the solution in the pixelopening K, so that the pixel defining layer 17 can define the lightemitting unit 14 within the pixel opening K.

In some embodiments, as shown in FIG. 2 , the light detecting unit 12,the switch unit 13, and the light emitting unit 14 are sequentiallydistributed along a direction away from the base substrate 11. Referenceis made to FIG. 3 and FIG. 4 , FIG. 3 is a front view of another arraysubstrate according to an embodiment of the present disclosure, and FIG.4 is a cross-sectional view of the portion a-a of the array substrateshown in FIG. 3 . Reference is made to FIG. 4 on the basis of FIG. 2 ,the array substrate further includes an encapsulation layer 18 which islocated on the side of the light emitting unit 14 away from the basesubstrate 11. The encapsulation layer 18 covers the light emitting unit14 and the pixel defining layer 17, and the encapsulation layer 18 isused to encapsulate the light emitting unit 14 of the array substrate.In some embodiments, the encapsulation layer 18 may be a thin filmencapsulation (TFE) layer or an encapsulation cover plate. The TFE layermay include an inorganic layer and an organic layer that are alternatelystacked. The inorganic layer may be made of transparent insulatingmaterials such as SiO₂, SiO_(x), SiN_(x), Al₂O₃, or SiO_(x)N_(x), theorganic layer may be made of organic resin, and the encapsulation coverplate may be a cover plate made of materials such as glass, which is notlimited in the embodiments of the present disclosure.

The array substrate according to the embodiments of the presentdisclosure may be a bottom emission array substrate or a top emissionarray substrate. When the switch unit and the light emitting unit aredistributed in a direction away from the base substrate, in the bottomemission array substrate, there is no overlapping region between theorthographic projection of the switch unit onto the base substrate andthe orthographic projection of the light emitting unit onto the basesubstrate, which avoids the switch unit from shielding the light emittedfrom the light emitting unit so as to affect the light output rate ofthe array substrate. In the top emission array substrate, even there isan overlapping region between the orthographic projection of the switchunit onto the base substrate and the orthographic projection of thelight emitting unit onto the base substrate, the switch unit does notshield the light emitted from the light emitting unit, which does notaffect the light output rate of the array substrate. The top emissionarray substrate has a higher aperture ratio relative to the bottomemission array substrate. Exemplarily, the bottom emission arraysubstrate may be as shown in FIG. 1 and FIG. 2 , and the top emissionarray substrate may be as shown in FIG. 3 and FIG. 4 . Those skilled inthe art can easily understand that, the array substrate shown in FIG. 1to FIG. 4 are only exemplary. In actual applications, both the bottomemission array substrate and the top emission array substrate mayinclude an encapsulation layer. Furthermore, in addition to thestructures shown in FIG. 1 to FIG. 4 , the array substrate may furtherinclude a pixel circuit and a protective layer which is located on thesidewall of the photosensitive layer. The protective layer may be madeof silicon oxide (SiO), silicon nitride (SiN), and the thickness of theprotective layer may range from 50 nm to 150 nm, which will not berepeated in the embodiment of the present disclosure.

In the embodiment of the present disclosure, the light detecting unit 12may perform light detection under the control of the switch unit 13. Theprinciple of light detection performed by the light detecting unit 12will be described below with reference to FIG. 1 to FIG. 4 .

The light detecting unit 12 is a photodiode with a PIN layer (that is,the photosensitive layer 122). The light detecting unit 12 may also becalled a PIN junction photodiode. The light detecting unit 12 is verysensitive to illumination and can accurately sense a light signal, andcan convert the light signal into an electrical signal based on thephotovoltaic effect. In the light detecting unit 12, the first electrode121 is used to sense a light signal, and thus the first electrode 121may be called a photosensitive electrode (or called a photosensitivesurface, etc.) of the light detecting unit 12. Reference is made to FIG.5 that shows a principle diagram of light detection performed by a lightdetecting unit 12 according to an embodiment of the present disclosure.In FIG. 5 , the P region corresponds to the P-type semiconductor layerof the light detecting unit 12, the I region corresponds to theintrinsic semiconductor layer of the light detecting unit 12, and the Nregion corresponds to the N-type semiconductor layer of the lightdetecting unit 12. The operating principle of the light detecting unit12 is as follows: when light is irradiated onto the first electrode 121,the energy of the light causes the electrons in the P region and theelectrons in the N region to transfer to generate electron-hole pairs.Under the action of the internal electric field of the I region, theelectrons (the energy thereof is hv) move toward the positively chargedN region and are accumulated in the N region, the holes move toward thenegatively charged P region and are accumulated in the P region, whichcauses a voltage difference (also called a photo-generated bias) betweenthe P region and the N region, each of the first electrode 121 and thesecond electrode 123 (that is, the LS layer) has a certain potential.

Reference is made to FIG. 6 that shows a graph of the illumination timet versus the potential U1 of the first electrode 121 when the light isirradiated to the first electrode 121, where the curve Q1 represents therelationship between the illumination time t versus the potential U1 ofthe first electrode 121 when the light with a wavelength of 600nanometers is irradiated to the first electrode 121, the curve Q2represents the relationship between the illumination time t versus thepotential U1 of the first electrode 121 when the light with a wavelengthof 800 nanometers is irradiated to the first electrode 121, the curve Q3represents the relationship between the illumination time t versus thepotential U1 of the first electrode 121 when the light with a wavelengthof 900 nanometers is irradiated to the first electrode 121, the curve Q4represents the relationship between the illumination time t versus thepotential U1 of the first electrode 121 when the light with a wavelengthof 1200 nanometers is irradiated to the first electrode 121, and thecurve Q5 represents the relationship between the illumination time tversus the potential U1 of the first electrode 121 when the white lightis irradiated to the first electrode 121. As can be seen from FIG. 6 ,when the light with different wavelengths is irradiated to the firstelectrode 121, the potential U1 generated by the first electrode 121 isdifferent.

Illumination can cause the potential of the first electrode 121 and thepotential of the second electrode 123 (that is, the LS layer) to change,and the change of the potential of the second electrode 123 may causethe control voltage Vg of the switch unit 13 (that is, the voltage ofthe control terminal 132, for example the gate voltage) to change, thechange of the control voltage Vg of the switch unit 13 may cause theoutput current Id of the switch unit 13 to change. Therefore, theintensity of illumination irradiated to the first electrode 121 (thatis, the intensity of the light irradiated to the first electrode 121)may be determined based on the amount of change of the output current Idof the switch unit 13 caused by illumination, so as to realize lightdetection. Reference is made to FIG. 7 that shows a graph of the controlvoltage Vg of the switch unit 13 versus the output current Id of theswitch unit 13. U2 represents the potential of the second electrode 123,each of the curves corresponds to one U2, and U2 increases in thedirection indicated by the arrow. It can be seen that the curvescorresponding to different U2 are different, and thus the potential ofthe second electrode 123 has significant influence on the thresholdvoltage Vth of the switch unit 13.

Reference is made to FIG. 8 that shows an equivalent circuit diagram ofan array substrate according to an embodiment of the present disclosure.In FIG. 8 , bias represents the first electrode 121 of the lightdetecting unit 12, and LS represents the second electrode 123 of thelight detecting unit 12. The control terminal (for example, the gate) ofthe switch unit 13 is electrically connected to the gate line (not shownin FIG. 8 ) in the array substrate, the second terminal S (for example,the source) of the switch unit 13 is electrically connected to the dataline (not shown in FIG. 8 ) in the array substrate, and the firstterminal D (for example, the drain) of the switch unit 13 iselectrically connected to the light emitting unit 14. Furthermore, thefirst terminal D of the switch unit 13 is also electrically connected toan assembly for detecting light located outside the array substrate. Theassembly for detecting light may be a chip or a functional component inthe chip, and the chip may be an integrated circuit chip. Reference ismade to FIG. 9 that shows a graph of the transfer characteristics of theswitch unit 13 according to an embodiment of the present disclosure.FIG. 9 takes the switch unit 13 being a TFT as an example, and the ONtransition region of the switch unit 13 is the SS region. When the lightis irradiated to the first electrode 121 of the light detecting unit 12,the photo-generated bias generated by the light detecting unit 12 haslittle influence on the switch unit 13, and thus the amount of change ofthe output current Id of the switch unit 13 is usually small. When theswitch unit 13 operates in the OFF region or in the ON region, theamount of change of the output current Id of the switch unit 13 causedby the light irradiated to the first electrode 121 of the lightdetecting unit 12 is usually difficult to measure. When the switch unit13 operates in the SS region, the amount of change of the output currentId of the switch unit 13 caused by the light irradiated to the firstelectrode 121 of the light detecting unit 12 is easy to measure, andthus the intensity of illumination irradiated to the first electrode 121of the light detecting unit 12 may be determined based on the amount ofchange of the output current Id of the switch unit 13 caused by thelight irradiated to the first electrode 121 of the light detecting unit12 when the switch unit 13 operates in the SS region, that is, theswitch unit 13 may be controlled to operate in the SS region, so thatthe switch unit 13 is used to control the light detecting unit 12 toperform light detection. The process of determining the intensity ofillumination based on the amount of change of the output current Id ofthe switch unit 13 caused by the light irradiated to the first electrode121 of the light detecting unit 12 may be performed by the assembly fordetecting light shown in FIG. 8 . With reference to FIG. 8 and FIG. 9 ,in the embodiment of the present disclosure, when the switch unit 13operates in the ON region, the switch unit 13 is in the on state, andthe switch unit 13 controls the light emitting unit 14 to emit light;when the switch unit 13 operates in the OFF region, the switch unit 13is in the off state; and when the switch unit 13 operates in the SSregion, the switch unit 13 is between the on state and the off state,and the switch unit 13 controls the light detecting unit 12 to performlight detection.

The process of controlling the light emitting unit 14 by the switch unit13 to emit light and the process of controlling the light detecting unit12 by the switch unit 13 to perform light detection are described belowwith reference to FIG. 1 to FIG. 9 .

The process of controlling the light detecting unit 12 by the switchunit 13 to perform light detection may include: firstly, applying apositive voltage to the first electrode 121 (that is, the bias) of thelight detecting unit 12 to make the PIN layer (that is, thephotosensitive layer 122) be forwardly biased, so as to remove theresidual charge in the PIN layer (which is equivalent to a wire when thePIN layer is forwardly biased, and thus the charge stored in the PINlayer is discharged); then, applying a control voltage Vg to the switchunit 13 to make the switch unit 13 operate in the SS region, andapplying a negative voltage to the first electrode 121 of the lightdetecting unit 12 to make the PIN layer be reversely biased; the PINlayer is equivalent to a capacitor when the PIN layer is reverselybiased, and can store charge. When the light is irradiated to the firstelectrode 121, the PIN layer stores charge and generates a bias voltage(which may refer to the operating principle of the light detecting unit12 described above), so that the potential of the second electrode 123changes, thereby causing the threshold voltage Vth of the switch unit 13to drift. In the case that the threshold voltage Vth of the switch unit13 drifts and the control voltage Vg of the switch unit 13 does notchange, the output current Id of the switch unit 13 will change in theSS region, and the amount of change of the output current Id of theswitch unit 13 before illumination and after illumination may bedetermined, and the intensity of illumination irradiated to the firstelectrode 121 may be determined based on the amount of change of theoutput current Id of the switch unit 13 before illumination and afterillumination. The experiments have proved that the signal intensitydetected by the array substrate according to the embodiments of thepresent disclosure is 2 to 3 orders of magnitude, or even 4 orders ofmagnitude greater than the signal intensity detected by the traditionalarray substrate. Therefore, the array substrate according to theembodiments of the present disclosure is beneficial to implementhigh-resolution detection.

The process of controlling the light emitting unit 14 by the switch unit13 to emit light may include: applying a control voltage Vg to theswitch unit 13 to make the switch unit 13 operate in the ON region, andapplying a positive voltage to the first electrode 121 of the lightdetecting unit 12 to make the PIN layer be forwardly biased. At thistime, the switch unit 13 controls the light emitting unit 14 to turn onso that the light emitting unit 14 emits light. When the switch unit 13operates in the ON region, the voltage difference generated in the PINlayer has little or no influence on the output current of the switchunit 13. Thus, when the switch unit 13 operates in the ON region, thephoto-generated bias of the PIN layer has no influence on the lightemitting effect of the light emitting unit 14, and thus has no influenceon the display effect of the array substrate. Therefore, the lightdetecting unit 12 and the light emitting unit 14 may share the switchunit 13.

In summary, with respect to the array substrate according to theembodiment of the present disclosure, the light emitting unit and thelight detecting unit share the switch unit in the pixel region, whichhelps to reduce the number of the switch units on the array substrate,thereby simplifying the structure of the array substrate.

The following is an embodiment of the method for manufacturing an arraysubstrate according to the present disclosure. For the method andprinciple for manufacturing an array substrate according to the presentdisclosure, reference may be made to the descriptions in the followingembodiments.

Reference is made to FIG. 10 that shows a flow chart of a method formanufacturing an array substrate according to an embodiment of thepresent disclosure. The method for manufacturing an array substrate maybe used to manufacture the array substrate shown in FIG. 1 or FIG. 4 .Referring to FIG. 10 , the method for manufacturing an array substratemay include step 101 and step 102.

In step 101, a base substrate having a pixel region is provided.

In step 102, a light detecting unit, a switch unit, and a light emittingunit are formed in the pixel region so that the light detecting unit andthe light emitting unit share the switch unit.

In summary, with respect to the method for manufacturing an arraysubstrate according to the embodiment of the present disclosure, thelight emitting unit and the light detecting unit share the switch unitin the pixel region, which helps to reduce the number of the switchunits on the array substrate, thereby simplifying the structure of thearray substrate.

In some embodiments, step 102 includes:

forming a light detecting unit in the pixel region;

forming a switch unit on the side of the light detecting unit away fromthe photosensitive side of the light detecting unit, where the switchunit is insulated from the light detecting unit, and the orthographicprojection of the light detecting unit onto the base substrate is atleast partially overlapped with the orthographic projection of theswitch unit onto the base substrate; and

forming a light emitting unit on the side of the switch unit away fromthe light detecting unit, where the light emitting unit is electricallyconnected to the switch unit.

In some embodiments, forming the light detecting unit in the pixelregion includes:

forming a first electrode, a photosensitive layer, and a secondelectrode in the pixel region, where the first electrode, thephotosensitive layer, and the second electrode are sequentially stackedin a direction away from the base substrate;

forming the switch unit on the side of the light detecting unit awayfrom the photosensitive side of the light detecting unit includes:

forming an active layer on the side of the light detecting unit awayfrom the photosensitive side of the light detecting unit; and

forming a control terminal, a first terminal, and a second terminal onthe side of the active layer away from the light detecting unit.

In some embodiments, the second electrode is made of a light-shieldingmaterial, and an orthographic projection of the second electrode ontothe base substrate is at least partially overlapped with an orthographicprojection of the active layer onto the base substrate.

In some embodiments, the orthographic projection of the second electrodeonto the base substrate covers the orthographic projection of the activelayer onto the base substrate.

In some embodiments, before forming the switch unit on the side of thelight detecting unit away from the photosensitive side of the lightdetecting unit, the method for manufacturing an array substrate furtherincludes:

forming an insulating layer on the side of the light detecting unit awayfrom the photosensitive side of the light detecting unit.

Correspondingly, forming the switch unit on the side of the lightdetecting unit away from the photosensitive side of the light detectingunit includes:

forming the switch unit on the side of the insulating layer away fromthe light detecting unit.

In some embodiments, before forming the light emitting unit on the sideof the switch unit away from the light detecting unit, the method formanufacturing an array substrate further includes:

forming a planarization layer on the side of the switch unit away fromthe light detecting unit.

Correspondingly, forming the light emitting unit on the side of theswitch unit away from the light detecting unit includes:

forming the light emitting unit on the side of the planarization layeraway from the light detecting unit.

The method for manufacturing an array substrate further includes:forming a pixel defining layer on the side of the planarization layeraway from the switch unit, where the light emitting unit is located in apixel opening defined by the pixel defining layer.

In some embodiments, the method for manufacturing an array substratefurther includes: forming an encapsulation layer on the side of thelight emitting unit away from the planarization layer.

All the above-mentioned optional technical solutions may be combined inany way to form an optional embodiment of the present disclosure, whichwill not be repeated here.

Reference is made to FIG. 11 that shows a flow chart of another methodfor manufacturing an array substrate according to an embodiment of thepresent disclosure. The method for manufacturing an array substrate maybe used to manufacture the array substrate shown in FIG. 1 or FIG. 3 .The embodiment of the present disclosure takes the manufacture of thearray substrate shown in FIG. 3 as an example for description. Referringto FIG. 11 , the method for manufacturing an array substrate may includesteps 201 to 207.

In step 201, a base substrate having a pixel region is provided.

The base substrate may be a transparent substrate. For example, the basesubstrate may be a rigid substrate made of optically transmissive andnon-metallic materials with a certain degree of robustness, such asglass, quartz, or transparent resin; or, the base substrate is aflexible substrate made of flexible materials such as polyimide (PI).

In step 202, a light detecting unit is formed in the pixel region.

Reference is made to FIG. 12 that shows a schematic diagram of the lightdetecting unit 12 being formed on the base substrate 11 according to anembodiment of the present disclosure. The light detecting unit 12includes a first electrode 121, a photosensitive layer 122, and a secondelectrode 123 that are sequentially stacked in a direction away from thebase substrate 11. The photosensitive layer 122 may be a PIN layer,including a P-type semiconductor layer, an intrinsic semiconductorlayer, and an N-type semiconductor layer that are sequentially stacked.The P-type semiconductor layer may be close to the first electrode 121or far away from the first electrode 121 relative to the N-typesemiconductor layer. The P-type semiconductor layer may be a P-typedoped a-Si film layer, and the thickness of the P-type semiconductorlayer may range from 10 nm to 20 nm. The intrinsic semiconductor layermay be an a-Si film layer, and the thickness of the intrinsicsemiconductor layer may range from 500 nm to 1000 nm. The N-typesemiconductor layer may be an N-type doped a-Si film layer, and thethickness of the N-type semiconductor layer may range from 10 nm to 20nm. The first electrode 121 may be made of transparent conductivematerials such as ITO, IZO, or ZnO:Al, and the thickness of the firstelectrode 121 may range from 50 nm to 130 nm. The second electrode 123is made of a light-shielding material such as Mo, Cu, Al, Au and alloymaterials thereof, and the thickness of the second electrode 123 mayrange from 200 nm to 400 nm.

Exemplarily, in the case that the P-type semiconductor layer may beclose to the first electrode 121 relative to the N-type semiconductorlayer, forming the light detecting unit 12 in the pixel region mayinclude the following step (1) to step (3).

In step (1), an ITO material layer with a thickness between 50 nm and130 nm is formed on the base substrate 11 by any of the processes suchas magnetron sputtering, thermal evaporation, or plasma enhancedchemical vapor deposition (PECVD), and the ITO material layer isprocessed by a one-time patterning process to obtain a first electrode121, the first electrode 121 is located in the pixel region of the basesubstrate 11.

In step (2), a P-type semiconductor material layer with a thicknessbetween 10 nm and 20 nm, an intrinsic semiconductor material layer witha thickness between 500 nm and 1000 nm, and an N-type semiconductormaterial layer with a thickness between 10 nm and 50 nm are sequentiallyformed on the side of the first electrode 121 away from the basesubstrate 11. The P-type semiconductor material layer, the intrinsicsemiconductor material layer, and the N-type semiconductor materiallayer are processed by a one-time patterning process to obtain theP-type semiconductor layer, the intrinsic semiconductor layer and theN-type semiconductor layer that are sequentially stacked with the firstelectrode 121, so as to obtain the photosensitive layer 122 (that is,the PIN layer 122). Forming the P-type semiconductor material layer mayinclude: firstly, depositing an intrinsic semiconductor material by aPECVD process to form an intrinsic semiconductor material layer, andthen performing a P-type doping on the intrinsic semiconductor materiallayer to obtain a P-type semiconductor material layer; or firstly,performing a P-type doping on an intrinsic semiconductor material toobtain a P-type semiconductor material, and then depositing a P-typesemiconductor material by a PECVD process to obtain a P-typesemiconductor material layer. The process of forming the N-typesemiconductor material layer is similar to this, and will not berepeated here. It is easy for those skilled in the art to understandthat the embodiment of the present disclosure is described by taking anexample in which the P-type semiconductor layer, the intrinsicsemiconductor layer, and the N-type semiconductor layer aresimultaneously formed. In actual applications, a semiconductor materiallayer may be processed to obtain a corresponding semiconductor layer(for example, the P-type semiconductor layer) every time that thesemiconductor material layer (for example, the P-type semiconductormaterial layer) is formed, which is not limited in the embodiment of thepresent disclosure.

In step (3), a metal Mo material layer with a thickness between 200 nmand 400 nm is formed on the side of the photosensitive layer 122 awayfrom the base substrate 11 by any of the processes such as magnetronsputtering, thermal evaporation or PECVD, and the metal Mo materiallayer is processed by a one-time patterning process to obtain the secondelectrode 123 that is stacked with the photosensitive layer 122.

In step 203, an insulating layer is formed on the side of the lightdetecting unit away from the photosensitive side of the light detectingunit.

Reference is made to FIG. 13 that shows a schematic diagram of theinsulating layer 15 being formed on the side of the light detecting unit12 away from the photosensitive side of the light detecting unit 12according to an embodiment of the present disclosure. The insulatinglayer 15 covers the light detecting unit 12, the side of the insulatinglayer 15 away from the light detecting unit 12 is a flat surface. Asshown in FIG. 13 , the side of the light detecting unit 12 away from thephotosensitive side of the light detecting unit 12 is the side of thelight detecting unit 12 away from the base substrate 11. The insulatinglayer 15 may include an organic insulating layer and an inorganicinsulating layer that are stacked. The organic insulating layer may bemade of resin, and the difference between the thickness of the organicinsulating layer and the thickness of the light detecting unit 12 mayrange from 1.2 μm to 3 μm. The inorganic insulating layer may be asingle-layered or multi-layered structure. For example, the inorganicinsulating layer may be a SiO₂ single-layered structure or a SiN/SiO₂multi-layered structure.

Exemplarily, forming the insulating layer 15 on the side of the lightdetecting unit 12 away from the photosensitive side of the lightdetecting unit 12 may include the following step (1) to step (2).

In step (1), a layer of resin is deposited on the side of the lightdetecting unit 12 away from the photosensitive side of the lightdetecting unit 12 as an organic insulating layer by any of the processessuch as magnetron sputtering, thermal evaporation or PECVD, the organicinsulating layer covers the light detecting unit 12.

In step (2), an SiN layer is first formed on the side of the organicinsulating layer away from the light detecting unit 12 by any of theprocesses such as magnetron sputtering, thermal evaporation or PECVD,and then an SiO₂ layer is formed on the side of the SiN layer away fromthe SiN layer by any of the processes such as magnetron sputtering,thermal evaporation or PECVD, and the SiN layer and the SiO₂ layer arestacked to form an inorganic insulating layer.

After the step (1) and step (2), an organic insulating layer and aninorganic insulating layer that are stacked may be obtained, and theorganic insulating layer and the inorganic insulating layer that arestacked form the insulating layer 15.

In step 204, a switch unit is formed on the side of the insulating layeraway from the light detecting unit, and the orthographic projection ofthe switch unit onto the base substrate is at least partially overlappedwith the orthographic projection of the light detecting unit onto thebase substrate.

Reference is made to FIG. 14 that shows a schematic diagram of theswitch unit 13 being formed on the side of the insulating layer 15 awayfrom the light detecting unit 12 according to an embodiment of thepresent disclosure. The orthographic projection of the switch unit 13onto the base substrate 11 is at least partially overlapped with theorthographic projection of the light detecting unit 12 onto the basesubstrate 11. In some embodiments, the orthographic projection of theswitch unit 13 onto the base substrate 11 covers the orthographicprojection of the light detecting unit 12 onto the base substrate 11. Asshown in FIG. 14 , the switch unit 13 includes an active layer 131, acontrol terminal 132, a first terminal 133, and a second terminal 134,where the control terminal 132, the first terminal 133, and the secondterminal 134 are located on the side of the active layer 131 away fromthe light detecting unit 12. The first terminal 133 and the secondelectrode 134 are distributed in the same layer, the first terminal 133and the second terminal 134 may be prepared through the same onepatterning process, and the first terminal 133 and the second terminal134 are electrically connected to the active layer 131 respectively. Theswitch unit 13 may be a TFT, as shown in FIG. 14 , the switch unit 13further includes a gate insulating layer 135 located between the activelayer 131 and the control terminal 132, and an interlayer dielectriclayer 136 located between the control terminal 132 and the firstterminal 133 and the second terminal 134. Each of the gate insulatinglayer 135 and the interlayer dielectric layer 136 has a communicablefirst connection hole and a communicable second connection hole. Thefirst terminal 133 (for example, the drain) is electrically connected tothe active layer 131 sequentially through the first connection hole inthe interlayer dielectric layer 136 and the first connection hole in thegate insulating layer 135, and the second terminal 134 (for example, thesource) are electrically connected to the active layer 131 sequentiallythrough the second connection hole in the interlayer dielectric layer136 and the second connection hole in the gate insulating layer 135. Theorthographic projection of the second electrode 123 onto the basesubstrate 11 covers the orthographic projection of the active layer 131onto the base substrate 11. The active layer 131 may be an oxide activelayer, an a-Si active layer, or a p-Si active layer. The oxide activelayer is for example an IGZO active layer or an ITZO active layer. Theportion of the active layer 131 where the first terminal 133 and thesecond terminal 134 are connected has been metallized. The gateinsulating layer 135 may be made of transparent insulating materialssuch as SiO₂, SiO_(x), SiN_(x), Al₂O₃ or SiO_(x)N_(x), the gateinsulating layer 135 may be a single-layered or multi-layered structure,and the thickness of the gate insulating layer 135 may range from 80 nmto 150 nm. The control terminal 132 may be made of Mo, Cu, Al, Au andalloy materials thereof, and the thickness of the control terminal 132may range from 200 nm to 400 nm. The interlayer dielectric layer 136 maybe made of transparent insulating materials such as SiO₂, SiO_(x),SiN^(x), Al₂O₃ or SiO_(x)N_(x), the interlayer dielectric layer 136 maybe a single-layered or multi-layered structure, and the thickness of theinterlayer dielectric layer 136 may range from 80 nm to 150 nm. Thefirst terminal 133 and the second terminal 134 may both be made of Mg,Ag, Mo, Cu, Al, Au and alloy materials thereof, and the thickness of thefirst terminal 133 and the thickness of the second terminal 134 mayrange from 200 nm to 400 nm.

Exemplarily, forming the switch unit 13 on the side of the insulatinglayer 15 away from the light detecting unit 12 may include the followingstep (1) to step (6).

In step (1), an IGZO material layer is formed on the side of theinsulating layer 15 away from the light detecting unit 12 by any of theprocesses such as magnetron sputtering, thermal evaporation or PECVD,and the IGZO material layer is processed by a one-time patterningprocess to obtain the active layer 131. The portion of the active layer131 where the first terminal and the second terminal are connected ismetallized by any of processes such as doping, plasma treatment, oratmosphere annealing, so as to increase the carrier concentration of theportion and to ensure an ohmic contact between the portion and thecorresponding electrode (for example, the first terminal or the secondterminal).

In step (2), an SiO₂ layer with a thickness between 80 nm and 150 nm isformed on the side of the active layer 131 away from the light detectingunit 12 as the gate insulating layer 135 by any of the processes such asmagnetron sputtering, thermal evaporation or PECVD.

In step (3), a Mo material layer with a thickness between 200 nm and 400nm is formed on the side of the gate insulating layer 135 away from thelight detecting unit 12 by any of the processes such as magnetronsputtering, thermal evaporation or PECVD, and the metal Mo materiallayer is processed by a one-time patterning process to obtain thecontrol terminal 132.

In step (4), an interlayer dielectric layer 136 is formed on the side ofthe control terminal 132 away from the light detecting unit 12. Theprocess of forming the interlayer dielectric layer 136 may refer to theprocess of forming the gate insulating layer 135.

In step (5), the interlayer dielectric layer 136 and the gate insulatinglayer 135 are processed by a one-time patterning process to form acommunicable first connection hole and a communicable second connectionhole in each of the interlayer dielectric layer 136 and the gateinsulation layer 135. The portion of the active layer 131 where thefirst terminal (for example, the drain) is connected is exposed throughthe first connection hole, and the portion of the active layer 131 wherethe second terminal (for example, the source) is connected is exposedthrough the second connection hole.

In step (6), a Mo material layer with a thickness between 200 nm and 400nm is formed on the side of the interlayer dielectric layer 136 awayfrom the light detecting unit 12 by any of the processes such asmagnetron sputtering, thermal evaporation or PECVD, and the Mo materiallayer is processed by a one-time patterning process to obtain the firstterminal 133 and the second terminal 134. The first terminal 133 iselectrically connected to the active layer 131 sequentially through thefirst connection hole in the interlayer dielectric layer 136 and thefirst connection hole in the gate insulating layer 135. The secondterminal 134 is electrically connected to the active layer 131sequentially through the second connection hole in the interlayerdielectric layer 136 and the second connection hole in the gateinsulating layer 135.

In step 205, a planarization layer is formed on the side of the switchunit away from the insulating layer.

Reference is made to FIG. 15 that shows a schematic diagram of theplanarization layer 16 being formed on the side of the switch unit 13away from the insulating layer 15 according to an embodiment of thepresent disclosure. The side of the planarization layer 16 away from theswitch unit 13 is a flat surface. The planarization layer 16 has ananode via G through which the first terminal 133 of the switch unit 13is exposed. The planarization layer 16 may be made of resin.

Exemplarily, a resin layer with a thickness between 2 μm and 3 μm isformed on the side of the switch unit 13 away from the insulating layer15 as the planarization layer 16 by any of the processes such asmagnetron sputtering, thermal evaporation or PECVD.

In step 206, a light emitting unit and a pixel defining layer are formedon the side of the planarization layer away from the switch unit, thelight emitting unit is located in the pixel opening defined by the pixeldefining layer, the light emitting unit is electrically connected to theswitch unit, and the light emitting unit and the light detecting unitshare the switch unit.

Reference is made to FIG. 16 that shows a schematic diagram of the lightemitting unit 14 and the pixel defining layer 17 being formed on theside of the planarization layer 16 away from the switch unit 13according to the embodiment of the present disclosure. The lightemitting unit 14 is located in the pixel opening K defined by the pixeldefining layer 17, the light emitting unit 14 includes an anode 141, anelectroluminescent layer 142, and a cathode 143 that are sequentiallystacked in a direction away from the base substrate 11. The anode 141 iselectrically connected to the first terminal 133 through the anode via Gin the planarization layer 16. The anode 141 may be made of Mg, Ag, Mo,Cu, Al, Au and alloy materials thereof. The electroluminescent layer 142may be made of electroluminescent materials. The cathode 143 may be madeof conductive materials such as ITO, IZO, and metal Ag. For example, thecathode 143 is an ITO/Ag/ITO multi-layered structure, where thethickness of the ITO film layer is 8 nm, the thickness of the Ag filmlayer is 100 nm, and the pixel defining layer 17 may be made of resinwith strong liquid repellency.

Exemplarily, forming the light emitting unit 14 and the pixel defininglayer 17 on the side of the planarization layer 16 away from the switchunit 13 may include the following step (1) to step (4).

In step (1), a layer of magnesium-silver alloy is deposited on the sideof the planarization layer 16 away from the switch unit 13 to obtain analloy material layer by any of the processes such as magnetronsputtering, thermal evaporation or PECVD, and the alloy material layeris processed by a one-time patterning process to obtain the anode 141which is electrically connected to the first terminal 133 through theanode via G.

In step (2), a layer of resin is deposited on the side of the anode 141away from the first terminal 133 to obtain a resin material layer by anyof the processes such as magnetron sputtering, thermal evaporation orPECVD, and the resin material layer is processed by a one-timepatterning process to obtain the pixel defining layer 17, the sidesurface of the anode 141 is located within the pixel defining layer 17,and the upper surface of the anode 141 is partially exposed through thepixel opening K.

In step (3), a layer of electroluminescent material is formed andprinted in the pixel opening K by an inkjet printing process, and theprinted electroluminescent material is dried to obtain anelectroluminescent layer 142.

In step (4), an ITO material layer, an Ag material layer, and an ITOmaterial layer that are sequentially stacked are formed on the side ofthe electroluminescent layer 142 away from the anode 141 by any of theprocesses such as magnetron sputtering, thermal evaporation or PECVD.The thickness of the ITO material layer may be 8 nm, and the thicknessof the Ag material layer may be 100 nm. The ITO material layer, the Agmaterial layer, and the ITO material layer are processed by a one-timepatterning process to obtain the cathode 143.

In step 207, an encapsulation layer is formed on the side of the lightemitting unit away from the planarization layer.

A reference may be made to FIG. 4 that shows a schematic diagram of theencapsulation layer 18 being formed on the side of the light emittingunit 14 away from the planarization layer 16. The encapsulation layer 18covers the light emitting unit 14 and the pixel defining layer 17. Theencapsulation layer 18 may be a TFE layer or an encapsulation coverplate. The TFE layer includes an inorganic layer and an organic layerthat are alternately stacked. The inorganic layer may be made oftransparent insulating materials such as SiO₂, SiO_(x), SiN_(x), Al₂O₃or SiO_(x)N_(x), and the organic layer may be made of organic resin, theencapsulation cover plate may be a cover plate made of materials such asglass.

Exemplarily, taking the encapsulation layer 18 being a TFE layer as anexample, forming the encapsulation layer 18 on the side of the lightemitting unit 14 away from the planarization layer 16 may include:depositing a layer of SiO_(x) on the side of the light emitting unit 14away from the planarization layer 16 to obtain an SiO_(x) material layerby any of the processes such as magnetron sputtering, thermalevaporation or PECVD, and processing the SiO_(x) material layer by aone-time patterning process to obtain the inorganic layer; printing alayer of organic resin on the side of the inorganic layer away from theplanarization layer 16 by an inkjet printing process, and drying theprinted organic resin to obtain the organic layer, thereby obtaining theencapsulation layer.

The one-time patterning process involved in the embodiments of thepresent disclosure includes photoresist coating, exposure, development,etching, and photoresist stripping. The processing of a material layer(for example, an ITO material layer) by the one-time patterning processincludes: firstly, coating the material layer (for example, the ITOmaterial layer) with a layer of photoresist to form a photoresist layer;next, exposing the photoresist layer with a mask, so that thephotoresist layer forms a completely-exposed region and a non-exposedregion; subsequently, adopting a developing process for processing, sothat the photoresist in the completely-exposed region is completelyremoved, and all the photoresist in the non-exposed region is retained;hereafter, etching a region, corresponding to the completely-exposedregion, on the material layer (for example, the ITO material layer) byan etching process; and stripping the photoresist in the non-exposedregion, so that a corresponding structure (for example, the firstelectrode 121) is obtained. Here, the description is given by taking thephotoresist as a positive photoresist. When the photoresist is anegative photoresist, the process of the one-time patterning process maymake reference to the description in this paragraph and will not berepeated in the embodiment of the present disclosure here.

In the method for manufacturing an array substrate according to theembodiments of the present disclosure, the order of the steps may beappropriately adjusted, and the steps may be correspondingly increasedor decreased as needed. Changed methods which can be easily expected byany person skilled in the art within the technical scope disclosed bythe present disclosure should be covered by the protection scope of thepresent disclosure, and thus will not be repeated herein.

In summary, with respect to the method for manufacturing an arraysubstrate according to the embodiment of the present disclosure, thelight emitting unit and the light detecting unit share the switch unitin the pixel region, which helps to reduce the number of the switchunits on the array substrate, thereby simplifying the structure of thearray substrate. With respect to the method for manufacturing an arraysubstrate according to the embodiment of the present disclosure, sincethe light detecting unit is manufactured first and then the switch unitis manufactured, the influence of the process of preparing the lightdetecting unit on the active layer of the switch unit may be avoided.

The following is an embodiment of the method for detecting light of thepresent disclosure. The method for detecting light and principle of thepresent disclosure may be referred to the descriptions in the followingembodiments.

Reference is made to FIG. 17 that shows a flow chart of a method fordetecting light according to an embodiment of the present disclosure.The method for detecting light may be used for the array substrateaccording to the above embodiments, and each of the pixel regions of thearray substrate is provided with a light detecting unit, a switch unitand a light emitting unit. The light detecting unit in each of the pixelregions and the light emitting unit in the pixel region share the switchunit in the pixel region. The light detecting unit includes a firstelectrode, a photosensitive layer, and a second electrode, and themethod for detecting light may be executed by an assembly for detectinglight. Referring to FIG. 17 , the method for detecting light may includesteps 301 to 304.

In step 301, the switch unit is controlled to operate in an ONtransition region, where the ON transition region is the region betweenan ON region and an OFF region of the switch unit.

In step 302, a voltage is applied to the first electrode of the lightdetecting unit, so that the second electrode of the light detecting unithas a potential, where the potential of the second electrode changesunder the action of the light irradiated to the first electrode, causingan output current of the switch unit to change.

In step 303, an amount of change of the output current of the switchunit is determined.

In step 304, an intensity of illumination irradiated to the firstelectrode is determined based on the amount of change of the outputcurrent of the switch unit.

In some embodiments, the light irradiated to the first electrode is thelight reflected by a fingerprint. After step 303, the method fordetecting light further includes: performing fingerprint detection basedon the amount of change of the output current of a plurality of theswitch units.

In summary, with respect to the method for detecting light according tothe embodiment of the present disclosure, the light emitting unit andthe light detecting unit share the switch unit in each of the pixelregions of the array substrate, which helps to reduce the number of theswitch units on the array substrate, thereby simplifying the structureof the array substrate.

Reference is made to FIG. 18 that shows a flow chart of another methodfor detecting light according to an embodiment of the presentdisclosure. The method for detecting light may be used for the arraysubstrate according to the above embodiments. Each of the pixel regionsof the array substrate is provided with a light detecting unit, a switchunit and a light emitting unit. The light detecting unit in each of thepixel regions and the light emitting unit in the pixel region share theswitch unit in the pixel region. The light detecting unit includes afirst electrode, a photosensitive layer, and a second electrode, and themethod for detecting light may be executed by an assembly for detectinglight. Referring to FIG. 18 , the method for detecting light may includesteps 401 to 405.

In step 401, the switch unit is controlled to operate in an ONtransition region, where the ON transition region is the region betweenan ON region and an OFF region of the switch unit.

In some embodiments, the assembly for detecting light may beelectrically connected to the control terminal (for example, the gate)of the switch unit, and the assembly for detecting light may apply acontrol voltage (for example, a gate voltage) to the switch unit to makethe switch unit operate in the ON transition region. When the switchunit operates in the ON transition region, the current transmitted tothe light emitting unit through the switch unit is not enough to turn onthe light emitting unit, and thus the light emitting unit is in the offstate and the light emitting unit does not emit light. The ON transitionregion is the region between an ON region and an OFF region of theswitch unit, and when the switch unit is a TFT, the ON transition regionis a subthreshold swing region.

In step 402, a voltage is applied to the first electrode of the lightdetecting unit, so that the second electrode of the light detecting unithas a potential, where the potential of the second electrode changesunder the action of the light irradiated to the first electrode, causingan output current of the switch unit to change.

In some embodiments, the assembly for detecting light may beelectrically connected to the first electrode of the light detectingunit, and the assembly for detecting light may apply a voltage to thefirst electrode of the light detecting unit. After the voltage isapplied to the first electrode, the photosensitive layer (for example,the PIN layer) of the assembly for detecting light can accumulatecharge, so that the second electrode of the assembly for detecting lighthas a potential.

In the embodiment of the present disclosure, when light is irradiatedonto the first electrode, the light detecting unit generates aphoto-generated bias which may cause the potential of the secondelectrode to change, and the change of the potential of the secondelectrode may cause the output current of the switch unit to change, thespecific principle thereof may be referred to the related descriptionsin FIG. 5 to FIG. 9 .

In some embodiments, before step 402, a positive voltage may be appliedto the first electrode of the light detecting unit to make thephotosensitive layer be forwardly biased, so as to remove residualcharge in the photosensitive layer, and then step 402 is performed,which may avoid the influence of the residual charge in thephotosensitive layer on the process of light detection.

In step 403, an amount of change of the output current of the switchunit is determined.

In some embodiments, when the switch unit is a TFT, the output currentof the switch unit is the leakage current of the switch unit. Theassembly for detecting light may be electrically connected to the firstterminal (that is, the drain) of the switch unit. The output current ofthe switch unit may be transmitted to the assembly for detecting lightthrough the first terminal of the switch unit. The assembly fordetecting light may determine the amount of change of the output currentof the switch unit based on the magnitude of the output current of theswitch unit before illumination and the magnitude of the output currentof the switch unit after illumination.

In step 404, an intensity of illumination irradiated to the firstelectrode is determined based on the amount of change of the outputcurrent of the switch unit.

The intensity of illumination irradiated to the first electrode is theintensity of light irradiated to the first electrode.

In some embodiments, the light detecting unit may maintain thecorrelation between the amount of change of the output current and theintensity of illumination. The light detecting unit may determine theintensity of illumination irradiated to the first electrode based on theamount of change of the output current of the switch unit and thecorrelation between the amount of change of the output current and theintensity of illumination.

In step 405, fingerprint detection is performed based on the amount ofchange of the output current of a plurality of the switch units.

When a finger is pressed on the light-emitting surface (for example, thebase substrate) of the array substrate, the fingerprint of the fingermay reflect the light emitted from the array substrate to generatereflected light, and the reflected light may enter the light detectingunit in at least one pixel region, and the reflected light reflected bythe “ridge” and “groove” of the fingerprint is different. The reflectedlight reflected by the “ridge” and “groove” of the fingerprint may enterthe light detecting unit in a different pixel region, causing the outputcurrent of the switch unit in the different pixel region to change, andthe amount of change of the output current of the switch unit in thedifferent pixel region is different. Therefore, the contour of the“ridge” and “groove” of the fingerprint may be imaged based on theamount of change of the output current of the switch unit in thedifferent pixel regions, thereby realizing fingerprint detection.

In the embodiment of the present disclosure, the light detecting unitcan also detect the ambient light where the array substrate is located,and the light detecting unit can transmit the intensity of the detectedambient light to the assembly for detecting light. When the arraysubstrate is applied to a smart terminal such as a mobile phone, theassembly for detecting light can adjust the screen brightness of thesmart terminal based on the intensity of the ambient light detected bythe light detecting unit, so as to realize the automatic adjustment ofthe screen brightness by the smart terminal, which will not be repeatedin the embodiment of the present disclosure.

In summary, with respect to the method for detecting light according tothe embodiment of the present disclosure, the light emitting unit andthe light detecting unit share the switch unit in each of the pixelregions of the array substrate, which helps to reduce the number of theswitch units on the array substrate, thereby simplifying the structureof the array substrate.

The following is an embodiment of the assembly for detecting light ofthe present disclosure, which may be used to execute the method fordetecting light of the present disclosure. For details that are notdisclosed in the embodiment of the assembly for detecting light of thepresent disclosure, reference is made to the embodiment of the methodfor detecting light of the present disclosure.

Reference is made to FIG. 19 that shows a block diagram of an assemblyfor detecting light 500 according to an embodiment of the presentdisclosure. The assembly for detecting light 500 may be configured toexecute the method for detecting light according to the embodiment shownin FIG. 17 or FIG. 18 . Referring to FIG. 19 , the assembly fordetecting light 500 may include, but is not limited to:

a controlling module 510, configured to control the switch unit tooperate in an ON transition region, where the ON transition region isthe region between an ON region and an OFF region of the switch unit;

a voltage applying module 520, configured to apply a voltage to thefirst electrode of the light detecting unit, so that the secondelectrode of the light detecting unit has a potential, where thepotential of the second electrode changes under the action of the lightirradiated to the first electrode, causing an output current of theswitch unit to change;

a first determining module 530, configured to determine an amount ofchange of the output current of the switch unit; and

a second determining module 540, configured to determine an intensity ofillumination irradiated to the first electrode based on the amount ofchange of the output current of the switch unit.

In some embodiments, the light irradiated to the first electrode is thelight reflected by a fingerprint. Reference is made to FIG. 20 , on thebasis of FIG. 19 , the assembly for detecting light 500 furtherincludes: a detecting module 550 configured to perform fingerprintdetection based on the amount of change of the output current of aplurality of the switch units.

In summary, with respect to the assembly for detecting light accordingto the embodiment of the present disclosure, the light emitting unit andthe light detecting unit share the switch unit in each of the pixelregions of the array substrate, which helps to reduce the number of theswitch units on the array substrate, thereby simplifying the structureof the array substrate.

Based on the same inventive concept, an embodiment of the presentdisclosure further provides a display device which includes the arraysubstrate shown in FIG. 1 to FIG. 4 . In some embodiments, the displaydevice further includes the assembly for detecting light shown in FIG.19 or FIG. 20 . The display device may be an electroluminescent displaydevice, for example, an OLED display device or a QLED display device.

The display device may be any product or component having a displayfunction, such as electronic paper, a display substrate, a displaypanel, a watch, a bracelet, a mobile phone, a tablet computer, atelevision, a display, a laptop computer, a digital photo frame and anavigator.

In the present disclosure, the term “electrically connected” refers to aconnection that is capable of transferring charge, but not necessarilyincludes charge transfer. For example, if A is electrically connected toB, it means that A is connected to B and charges can be transferredbetween A and B, whereas the charge transfer does not necessarily occurbetween A and B. The term “at least one” means one or more than one, andthe term “a plurality of” means two or more, unless otherwise expresslyprovided. The terms such as “first”, “second” and “third” are merely fora descriptive purpose, and cannot be understood as indicating orimplying a relative importance.

It may be understood by an ordinary person skilled in the art that allor part of steps in the above embodiments may be completed by hardwareor by a program instructing relevant hardware. The program may be storedin a computer-readable storage medium which may be a read-only memory, amagnetic disk, an optical disc or the like.

The above are merely exemplary embodiments of the present disclosure,but are not intended to limit the present disclosure. Any modifications,equivalent replacements and improvements made within the spirits andprinciples of the present disclosure should be included within the scopeof protection of the present disclosure.

What is claimed is:
 1. An array substrate, comprising: a base substratehaving a pixel region; and a light detecting unit, a switch unit, and alight emitting unit that are located in the pixel region, wherein thelight emitting unit is electrically connected to the switch unit, thelight detecting unit is insulated from the switch unit, and a currentgenerated by the light detecting unit under irradiation of light affectsan output current of the switch unit, so that the light detecting unitand the light emitting unit share the switch unit.
 2. The arraysubstrate according to claim 1, wherein, the switch unit is located on aside away from a photosensitive side of the light detecting unit, and anorthographic projection of the light detecting unit onto the basesubstrate is at least partially overlapped with an orthographicprojection of the switch unit onto the base substrate.
 3. The arraysubstrate according to claim 2, wherein, the orthographic projection ofthe switch unit onto the base substrate covers the orthographicprojection of the light detecting unit onto the base substrate.
 4. Thearray substrate according to claim 2, wherein, the light detecting unitcomprises a first electrode, a photosensitive layer, and a secondelectrode that are sequentially stacked in a direction close to theswitch unit; and the switch unit comprises an active layer, a controlterminal, a first terminal, and a second terminal, wherein the controlterminal, the first terminal, and the second terminal are located on aside of the active layer away from the light detecting unit, and one ofthe first terminal and the second terminal is a source, and the otherthereof is a drain.
 5. The array substrate according to claim 4,wherein, the second electrode is made of a light-shielding material, andan orthographic projection of the second electrode onto the basesubstrate is at least partially overlapped with an orthographicprojection of the active layer onto the base substrate.
 6. The arraysubstrate according to claim 5, wherein, the orthographic projection ofthe second electrode onto the base substrate covers the orthographicprojection of the active layer onto the base substrate.
 7. The arraysubstrate according to claim 4, wherein, the light emitting unit is anelectroluminescent unit, and the first terminal of the switch unit iselectrically connected to an anode of the light emitting unit.
 8. Thearray substrate according to claim 2, wherein the array substratefurther comprises: an insulating layer located between the lightdetecting unit and the switch unit; a planarization layer locatedbetween the switch unit and the light emitting unit; and, a pixeldefining layer located on a side of the planarization layer away fromthe switch unit, wherein the light emitting unit is located in a pixelopening defined by the pixel defining layer.
 9. The array substrateaccording to claim 1, wherein, the light detecting unit, the switchunit, and the light emitting unit are sequentially distributed in adirection away from the base substrate, and the array substrate furthercomprises: an encapsulation layer located on a side of the lightemitting unit away from the base substrate.
 10. An assembly fordetecting light for use in the array substrate according to claim 1,wherein the light detecting unit of the array substrate comprises afirst electrode, a photosensitive layer, and a second electrode, whereinthe assembly for detecting light comprises: a controlling circuit,configured to control the switch unit to operate in an ON transitionregion, wherein the ON transition region is a region between an ONregion and an OFF region of the switch unit; a voltage applying circuit,configured to apply a voltage to the first electrode of the lightdetecting unit, so that the second electrode of the light detecting unithas a potential, wherein the potential of the second electrode changesunder the action of the light irradiated to the first electrode, causingan output current of the switch unit to change; a first determiningcircuit, configured to determine an amount of change of the outputcurrent of the switch unit; and a second determining circuit, configuredto determine an intensity of illumination irradiated to the firstelectrode based on the amount of change of the output current of theswitch unit.
 11. The assembly for detecting light according to claim 10,wherein the light irradiated to the first electrode is light reflectedby a fingerprint, and the assembly for detecting light furthercomprises: a detecting circuit, configured to perform fingerprintdetection based on the amount of change of the output current of aplurality of the switch units.
 12. A display device, comprising: thearray substrate according to claim
 1. 13. A method for detecting lightfor use in an array substrate, wherein the array substrate comprises: abase substrate having a pixel region; and a light detecting unit, aswitch unit, and a light emitting unit that are located in the pixelregion, and the light detecting unit and the light emitting unit sharethe switch unit, the light detecting unit of the array substratecomprises a first electrode, a photosensitive layer, and a secondelectrode; wherein the method for detecting light comprises: controllingthe switch unit to operate in an ON transition region, wherein the ONtransition region is a region between an ON region and an OFF region ofthe switch unit; applying a voltage to the first electrode of the lightdetecting unit, so that the second electrode of the light detecting unithas a potential, wherein the potential of the second electrode changesunder the action of the light irradiated to the first electrode, causingan output current of the switch unit to change; determining an amount ofchange of the output current of the switch unit; and determining anintensity of illumination irradiated to the first electrode based on theamount of change of the output current of the switch unit.
 14. Themethod for detecting light according to claim 13, wherein, the lightirradiated to the first electrode is light reflected by a fingerprint,and after determining the amount of change of the output current of theswitch unit, the method for detecting light further comprises:performing fingerprint detection based on the amount of change of theoutput current of a plurality of the switch units.
 15. A method formanufacturing an array substrate, comprising: providing a base substratehaving a pixel region; forming a light detecting unit, a switch unit,and a light emitting unit in the pixel region, wherein the lightemitting unit is electrically connected to the switch unit, the lightdetecting unit is insulated from the switch unit, and a currentgenerated by the light detecting unit under irradiation of light affectsan output current of the switch unit, so that the light detecting unitand the light emitting unit share the switch unit.
 16. The method formanufacturing the array substrate according to claim 15, wherein;forming the light detecting unit, the switch unit, and the lightemitting unit in the pixel region so that the light detecting unit andthe light emitting unit share the switch unit, comprises: forming thelight detecting unit in the pixel region; forming the switch unit on aside of the light detecting unit away from a photosensitive side of thelight detecting unit, wherein an orthographic projection of the lightdetecting unit onto the base substrate is at least partially overlappedwith an orthographic projection of the switch unit onto the basesubstrate; and forming the light emitting unit on a side of the switchunit away from the light detecting unit.
 17. The method formanufacturing the array substrate according to claim 16, wherein,forming the light detecting unit in the pixel region comprises: forminga first electrode, a photosensitive layer, and a second electrode in thepixel region, wherein the first electrode, the photosensitive layer, andthe second electrode are sequentially stacked in a direction away fromthe base substrate; forming the switch unit on the side of the lightdetecting unit away from the photosensitive side of the light detectingunit comprises: forming an active layer on the side of the lightdetecting unit away from the photosensitive side of the light detectingunit; and forming a control terminal, a first terminal, and a secondterminal on a side of the active layer away from the light detectingunit, wherein one of the first terminal and the second terminal is asource, and the other thereof is a drain.
 18. The method formanufacturing the array substrate according to claim 16, wherein, beforeforming the switch unit on the side of the light detecting unit awayfrom the photosensitive side of the light detecting unit, the method formanufacturing an array substrate further comprises: forming aninsulating layer on the side of the light detecting unit away from thephotosensitive side of the light detecting unit; forming the switch uniton the side of the light detecting unit away from the photosensitiveside of the light detecting unit comprises: forming the switch unit on aside of the insulating layer away from the light detecting unit.
 19. Themethod for manufacturing the array substrate according to claim 16,wherein, before forming the light emitting unit on the side of theswitch unit away from the light detecting unit, the method formanufacturing an array substrate further comprises: forming aplanarization layer on the side of the switch unit away from the lightdetecting unit; forming the light emitting unit on the side of theswitch unit away from the light detecting unit comprises: forming thelight emitting unit on a side of the planarization layer away from thelight detecting unit; the method for manufacturing an array substratefurther comprises: forming a pixel defining layer on the side of theplanarization layer away from the switch unit, wherein the lightemitting unit is located in a pixel opening defined by the pixeldefining layer.
 20. The method for manufacturing the array substrateaccording to claim 15, wherein the method for manufacturing the arraysubstrate further comprises: forming an encapsulation layer on a side ofthe light emitting unit away from the base substrate.